Compass



S. E; ANDREWS.

COMPASS.

APPLICATION FILED MAY6,1919.

mafia, Patented May 491920.

SEARLE E. ANDREWS, 0F PITTSBURGH, PENNSYLVANIA.

COMPASS.

Specification of Letters Patent.

Patented May a, 192% Application filed May 6, 1919. Serial N0. 295,051.

To all whom it may concern:

Be it known that I, SEARLE E. ANDREWS, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Compasses, of which the following is a specification.

My invention relates to improvements in compasses, and has particular reference to an overhead compass for aeroplanes or other flying machines. 4

An important object of the invention is to provide a compass of' the above-mentioned character, which may be arranged above the head of the operator or pilot, and secured to the sustaining plane or other element of the flying machine at a substantial distance from the motor, gas tank or other metallic parts of the flying machine so that its operation will not be destroyed or seriously impaired.

A further object of the invention is to provide a compass of the above-mentioned character, so constructed that the observer may read the same by looking through its bottom.

Other objects and advantages of the invention will be apparent during the course 313 of the following description.

In the-accompanying drawings forming a part of this specification, and in which like numerals are employed to designate like parts throughout the same:

Figure 1 is a transverse sectional 'view through a compass embodying my invention' 2 is a bottom plan view of the compass; and,

Fig. 3 is a side elevation of the same in he casing 5 by means of a screw 12, this post and screw being formed of non-magnetic material.

The numeral 13 designates a pivoted magnetic element, preferably in the form of an annular dial, tapering downwardly, as shown. This dial is provided upon its outer surface or periphery with the letters N, S, E, W, indicating north, south, east and west. This dial turns in proximity to a stationary indicating element 14, which may be formed upon the shell 7, upon the inner or outer surface thereof.

The magnetic element further comprises a magnetic bar 15, secured to the top thereof, and this bar carries a' pivot element 16, operating within a recess 17 in the post 11. The magnetic element is thus free to turn horizontally and its vibration or undue oscillation is prevented by filling the casing 5 and shell 7 with the liquid, which may be alcohol, kero ene or the like. i

The casing 5 is secured to the lower surface of the sustaining plane 18 of the aeroplane and may be attached thereto by screws or bolts 19, passing through the flange 6. The casing 5 and ring 9 preferably do not project below the lower surface of the sustaining plane while the shell 7 projects below the same, to enable the operator to readily see through the same. The compass is preferably mounted at a point equi-distantly spaced from the ends of the sustaining plane and preferably in front of the pilots seat or sufficiently in advance of him so that he may readily observe the same by looking upwardly. The compass is also arranged a substantial distance from the motor and gas tank and therefore its operation is not seriously impaired by the presence of the same.

In using the device, the magnetic element is retained in a position pointing due north and south, whlle the casing 5 and elements carried thereby may turn with relation to the magnetic element. The operator can readily observe the extent of turning movement of the casing 5 and associlsittgd elements by looking up through the she It is to be understood that the form of my invention herewith shown and described is to be taken as the preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the sub'oined claims. I

aving thus described my invention, I claim:

1. An overhead compass for aeroplanes or the like, comprising a casing having a transparent bottom, and a magnetic element casing, and a pivoted magnetic element bearing indicia arranged wlthin the shell and casing, the indicia upon said magnetic element being visible through said transparent shell. v

3. An overhead compass foraeroplanes or parent bottom, said transparent bottom be ing provided with a stationary indicator, and a pivoted magnetic element arranged within the casing and embodying an annular dial bearing indicia, said indicia being visible through the transparent bottom.

4'. An overhead compass for aeroplanes or the like, comprising a casing having a transparent bottom, a magnetic element bearing indicia upon its under face pivoted within the casing, and a fluid within the casing to prevent undesirable movement of the ma netic element, said indicia being visib e through said transparent bottom.

In testimony whereof I aflix my signature in presence of two witnesses.

SEARLE E. ANDREWS. 

